The present invention is directed to novel substances intended to modulate the immune response drawn on the types of chemical entities previously demonstrated to have that type of activity. Isoprinosine.RTM. (A), Gordon U.S. Pat. No. 3,646,007 is an immunomodulator demonstrated to have effects mainly on T-cells. Levamisole (B) has also been shown to have effects mainly on T-cells. ##STR3##